利用相位光栅的衍射检测啁啾飞秒激光脉冲

Measuring Chirped Femtosecond Laser Pulse by the Diffraction of a Grating

分析了一种0ˉπ相位光栅在啁啾飞秒激光脉冲照射下的菲涅耳衍射.通过选择相位光栅的结构,可以使衍射光的±1级分量最大.提取±1级衍射分量,并通过两反射镜将这束光在远处干涉.当飞秒激光脉冲的宽度一定时干涉条纹的强度与飞秒激光脉冲的啁啾系数有关.通过检测干涉条纹的强度,可以间接测量飞秒激光脉冲的啁啾系数.

The Fresnel diffraction of a 0-π phase grating under chirped femtosecond laser pulse illumination is analyzed. By choosing special structure of the phase grating, the diffraction light mainly contains ± 1 order components. ± 1 order diffraction components are extracted, and these two light beams are directed to interfere in the far region via two mirrors. The intensity distribution of the interference stripes is influenced by the chirp parameter of the femtosecond pulse when the width of the pulse is fixed. By detecting the interference stripe intensity, the chirp parameter of the femtosecond pulse can be measured indirectly.